I don’t know how to trust an app. Like, how would I make that decision?

When I used Android, I just didn’t install things unless I really, really wanted them, and they were popular enough that I figured security researchers would likely be looking at them closely. (Which, of course, was a great incentive to keep using Google’s ecosystem for everything.)

I tried iOS a few years ago, and one of the big differences is that I’m a lot more confident about trying random apps; I know there’ll still be shady apps, but Apple’s vetting and the iOS security model give me a lot more confidence. I’ve installed (and paid for) a lot more apps as a result; my phone’s much more usable to me.

Like, how do you decide which apps to trust on your PC? While Windows does have a store, I'd wager the majority of installs are still done by downloading .exe files off the software's homepages. Executable binaries that run with full privileges, with minimal permission granularity, no less.

Somehow we're not discussing prohibiting filesystem access for personal computers? Why is this an issue for smartphones, a.k.a. a pocket-sized personal computer?

Microsoft is slowly migrating Win32 into the store with each W10 release.

Inertia (the mass of already existing unsandboxed software) probably makes securing the (Windows) PC platform a lost cause.

If Windows had proper filesystem sandboxing enforced on applications, ransomware would disappear overnight

For example, I largely trust anything on F-Droid and various other open source apps.

Well, its a matter of degrees. I might want an app that I trust to have access to photos, but not my whole SD Card. That hasn't really been possible in the past.

And we've seen that apps that are trustworthy can be bought and sold, sometimes by companies that are very untrustworthy.

While trying to achieve that control, does this change really allow your most trusted apps to keep the same level of utility? It doesn't sound like it, for example it sounds like Termux will no longer be as useful

If it even can be made safe at all. I would have thought that Meltdown/Spectre would have made it very apparent by now that trying to perfectly isolate two programs on the same machine is like trying to make a colander float.